JPS5850548A - Electrostatic image developing method - Google Patents

Abstract

PURPOSE:To obtain a multicolor image free from fog, by selectively developing each of electrostatic latent images formed on an image bearing material different in polarity with each of oppositely charged colored particles, respectively. CONSTITUTION:A photoreceptor made by laminating 2 photoconductive layers different from each other in spectral sensitivity on a conductive substrate is subjected to primary charging of a prescribed polarity and then, secondary charging opposite in polarity to form an electric double layer in each photoconductive layer so as to arrange each dipole moment in the direction opposite to each other. The photoreceptor is exposed to the light image of an original to form a surface potential distribution having almost 0 value on the part corresponding to the background of the original, and each opposite polarity on the electrostatic latent image part corresponding to each color image, thus permitting the latent image thus formed to be compositely developed and this image to be charged with a corona charger to arrange the charge to one polarity, and transferred onto a recording paper and fixed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrostatic latent development method, particularly to a multicolor image development method.

A typical example of representing electrostatic latent scratches in a multicolor image is a color image using an electrophotographic method.

Tore K passes the original document through an optical filter to separate the colors, uses this separated light as exposure, and combines the steps of charging exposure, development, and transfer with development using yellow, magenta, cyan, and black colored toners. This is done by repeating it one after another four times. Another method is to create electrostatic latent images of different polarities on the same photoreceptor and develop them with black and red toners.

These multicolor images are advantageous because they can add color information compared to black and white information, but because it is usually necessary to use a developer 6 for each color, (1) the machine becomes larger; , high cost and null.

(2) It is necessary to guarantee color misregistration accuracy through repeated operations.

0) It takes an hour longer to copy one sheet.

There are problems like this.

For this reason, attempts have been made to make the developing device more compact by mixing two different color developers in the same developing device (for example, Japanese Patent Publication No. 55-30625); Mere mixing of two different color developers used in the example causes the following drawbacks.

α) Development occurs even in areas where there is no electrostatic latent image, that is, fogging occurs.

(2) Other developers are mixed into the developer constituting the developed image, resulting in poor color, that is, color turbidity.

Another object of the present invention is to provide a method for developing an electrostatic image that does not cause fogging when developed using a photocoat.
It is an object of the present invention to provide a method for developing electrostatic charge gI that does not cause color clouding when color particles having different charge polarities are used for development.

Still another object of the present invention is to provide an electrostatic image developing method that can produce sharp images when developed using colored particles having charge polarities KJ% of each other.

The above-mentioned objects of the present invention are to selectively extract colored particles charged to one polarity from colored particles having charged polarities Kff to each other, and use the extracted colored particles to absorb the true polarity of the electrostatic charge of the support. This is achieved by an electrostatic image developing method characterized by developing an electrostatic latent image of one polarity of the latent image.

One of the problems in developing using colored particles having different charging polarities (hereinafter referred to as composite developer) is the problem of fogging caused by the developer adhering to non-image areas.

This problem will be explained below using drawings.

Figure 1 shows the relationship between the potential of the electrostatic latent image and the amount of developer contributing to development. The horizontal axis represents the potential of the electrostatic latent image, and the vertical axis represents the amount of developer contributing to the development. Indicate quantity. Curve I represents the amount of negatively charged developer that adheres to the electrostatic latent image with positive potential, and curve ■
represents the amount of positively charged development that adheres to a negative potential electrostatic latent image.

In the gi diagram, the shaded area ■ indicates the S portion of the fog. If an electrical bias K is simply applied to a developer support (for example, a developing sleeve) in order to remove the generated fog, then the am agent of the opposite polarity will adhere to the support and fog will occur. That is, the fog cannot be removed by electrical bias.

Therefore, a means for selectively extracting only one of the developers was provided, and the extracted 3J developer was extracted using the method used for conventional one-component developers! By performing an I-image, the problem of fogging can be solved.

The present invention will be described in detail below using the drawings. In FIG. 2, l is a photosensitive drum with a photoconductor provided on its surface;
2 indicates a developing device. The IA converter 2 is composed of a developing roller 2-b and a supply roller 2-a, and the photosensitive drum 1, the developing roller 2-b, and the supply roller 2-a each rotate in the direction of the arrow. Note that in Figure 2, e and θ indicate positively and negatively charged colored particles. The roller 2-a that supplies the detected composite developer electrically supplies only the developer with a specific polarity from the # roller onto the developing roller 2-b by the rotation of the roller and the action of a certain magnet inside it. That is,
Move by applying DC voltage.

The relationship between the amount of movement of the tDQ agent from the supply a-52-a to the developing roller 2-b and the voltage applied by electrical means is a.
It is similar to Figure I1, and in order to move only a specific developer, a potential difference of a certain magnitude or more (zooV ~ tKV) is required.
It is necessary to provide

In order to ensure this movement, in addition to contacting the developer on the supply roller 2-a, the 9IJ should be allowed to fly.
b Move it up. Alternatively, it is effective to include a magnetic material in one or both of the composite developers. The content of the magnetic material at this time is such that the latter can be used to effectively perform triboelectrification, transport, prevention of scattering, etc. of the composite developer. Also, the movement of the composite developer is prohibited! ll! In some cases, small lumps containing different polarities are generated, and for this, when an alternating electric field is superimposed on the DC voltage shown in Figure 2, the agglomeration of the composite developer is loosened and only a specific developer can be more easily removed. It can be moved.

A developing method in which the electrostatic latent image and the developer held on the developer carrier are opposed to each other with a space between them and developed under an alternating electric field ( For example, JP-A-55-18656 and JP-A-55-18657.
No. 18658, No. 18658, No. 18659, US Pat. No. 3,890,929);
A typical method is to bring an electrostatic latent image into contact with a developer and develop under a low-frequency alternating electric field. These techniques make it possible to reliably attach only the polar developer to be attached to the electrostatic latent recording material by applying RN or vibration to the developer. In addition, the use of an alternating electric field has an excellent effect on sharpening the image.Positive or negative electrostatic latent images may be developed with a composite developer of the same color, but depending on the polarity of the electrostatic latent image, Developing may be performed using a composite developer having a different color.

This allows more information to be obtained. In addition, in the development process, development using a developer charged to one polarity may be repeated sequentially, but if it is possible to retain electrostatic latent images of both polarities, simultaneous development using a composite developer is more efficient. It is true. To do this, the configuration on the device f/jll! You can do it as shown in Figure 3.

In the fE3 diagram, l indicates a photoreceptor and 2 indicates a developing device. The developing device 2 is provided with two developing rollers 2-b and 2-o, each of which holds a developer having a polarity of 14. Further, 2-& indicates a supply roller, and the photoreceptor 11 developing roller 2-b and 2-o supply roller 2-a each rotate in the direction of the arrow.

Bipolar electrostatic latent image on photoreceptor 1 [developing rollers 2-b, 2
-A with different polarity static 1! Latent image t - Develop.

The development is carried out by the means normally used for component development, ie, the contact development method in which the electrostatic latent image is brought into contact with the developer previously formed on the development roller, or the non-contact development method in which no contact is made. Furthermore, when the developer contains a magnetic substance during development, it is effective to carry out the development under a magnetic field.

The developer used in the above development method is also called a bipolar developer! In order to develop the image with the same electrostatic latent image potential of A polarity, it is preferable that the characteristics of both the images are similar except for the charging polarity. From this, both are 5-20
Conditions such as a particle size of μ, a charge amount difference of 0.2 to 20/1 c/H, a similar magnetization strength, and a similar dielectric constant of 72 may be obtained. As a method for producing the agent, for example, JP-A-51-42539 and JP-A-53-
The techniques disclosed in Publications No. 118051 and No. 53-118053 can be applied.

The composite developer used in the present invention will be explained below.

Honyumei's composite developers are broadly divided into microcapsule developers and powder developers.

The former type of microcapsule developer generally has a synthetic resin film on the outside of a core material, and at least one of the films contains a magnetic material.

Particularly preferably, a first wall film mainly made of a film-forming polymer material is provided on the outside of the core material, and further, the outside i1 of the first wall film contains a magnetic material and is mainly made of synthetic resin. This is a developer provided with a 1112 wall film. The encapsulation method includes known microencapsulation methods, such as the complex coacelvage method; the simple coacelvage method;
Poly! by pH change, solvent change, and solvent removal! - Phase separation methods from water-soluble or aqueous dispersions such as insolubilization; interfacial polymerization methods;

Film-forming polymeric substance (e.g. 7 Ravi 7 rubber) adjusted to a predetermined pH (alkaline side), concentration and temperature
A non-aqueous solution or non-aqueous dispersion of the colorant is added to the aqueous solution for fractional emulsification, and to this is added a film-forming polymeric material (e.g. gelatin) which is a gelling and isoelectric colloid adjusted to the same concentration and temperature. Add an aqueous solution.Next, make the PM of this mixture acidic to cause phase separation. By doing this, the inner polymer substance is precipitated on the shoulders of the droplets of the non-aqueous solution or dispersion of the colorant, so next!
After cooling, a curing agent (Hokumarin) is added to make the solution fully caustic and the temperature of the solution is raised to harden the precipitate. moreover,
The desired toner is obtained by adding at least magnetic particles and a synthetic resin emulgene to the obtained capsule liquid, uniformly dispersing the mixture, and then spray drying the mixture.

Colorants used in the core material include inorganic pigments, organic pigments, direct dyes, acid dyes, basic dyes, mordants, acid mordant dyes, disperse dyes, and oil-soluble dyes. Specific examples include black pigments such as carbon black, acetylene black, Larepblack, Kurofune, mineral black, aniline black, and cyanine black, and yellow pigments such as chrome yellow, zinc yellow, barium materate, and cadmium. Yellow, lead - cyanamide 1 calcium leadate ~
Su7 Thor Eo-B, Hansa Yellow 3G, Hansa Yellow 〇, Hashisa Yellow GR, Hansa Elome, Hansa Elo A-'RM1 Hansa Yellow 31 Pigment Yellow L1
Benzine Yellow, Benzine Yellow 01 Benzine Yellow O
R, Permanent Yellow NoG % Palkan 7 Ast Yellow 501 Palkan 7 Ast Yellow R1 Tartrazine Lake, Quinoline A4 Lake, Acid Yellow 5GL
s permanent erotic? GL, Permanent Yellow Ta (To), Permanent Yellow HR1 Anthravilly no Gin Yellow, etc. 1 Red pigments include red pigment, red lead, chain vermilion, cadmium red, permanent red 411, para red, fire red - vermilion, para chlorol) 2) vs. 7
x-Rin Red 1 Resolfa Cis Scarlet G1
Brilliant 7 Assis Scarlet, Brilliant 7 Carmine BS, Permanent Red 121% Permanent Silette IF4R, Permanent Red IIIRL, Bar! Nene F Red 1■ Le, Permanent Red ν01, Fasciscare) 71), Palcan 7 Astorbin 1, Eosin Lake, Rhodamine Lake, Rhodamine Lake Y, 7 Rizarin Lake, Thioin Dibred B.

Thioindigo maroon, permanent red 7G! I
s PV power t :/ HRQ J', as blue pigments, ultramarine, navy blue, cobalt blue, alkali blue lake, peacock blue lake, Victoria blue lake,
Metal-free 7 thalocyanine blue, phthalocyanine blue,
77 St. Sky Blue, Indance Tremble-REl
Indance Stremburu-B8, Indigo, etc. are mentioned, and as a rough yellow dye, O, Ko, (Color Index) Direct Yellow 98.0. Engineering, Direct Yellow 89
, O,1, Direct Yellow 88 (direct dye),
0, Engineering, Acid Yellow 1% O, X, Acid Yellow 3, o, Engineering, Acid Yellow 7 (more acidic dyes)
, O, X, Basic Yellow 1% O, Eng, Basic Yellow 2, Q, Eng, Basic Yellow 11 (or more
1fit dye), o, engineering, modern yellow 26
(tl&dye/acidic mordant dye), O,
,X,De(X Perth Yellow 4 (disperse dye>)
O, X, Tsurubenge Yellow 2.0. Solvent Yellow 6, o.

As a red dye, such as Solvent Yellow 14 (oil-soluble dye), 0. :1. Direct Red 1.0. I
.

Direct Red 2, Q, X, Direct Red Reef, (
Direct dye >, O, engineering, acid red 8.0゜1,
Acid Red 13, C0 Engineering, Acid Red 14, (
Acid dyes), a, X, Basic Red 2.0,
Engineering, Basic Lettu Y14, OoX, Basic Red 27 (all basic dyes), 0. Engineering, modern tread 21
(Mordant/Acid mordant dye), O,! , Disperse Red 1% O0 process, Disperse Red) T4, a, process, Disperse Red 5 (more than % disperse dyeing), o, x, Tsurubenge Red 1.0. As blue dyes, such as Solvent Red 3.0, Solvent Red 8 (oil-soluble dyes), a, X, Direct Blue 1so, x.

Dairef) Blue 6.0. Engineering, direct blue n (or more direct dye), a, engineering, acid blue 1.0°1.7
Shitsur Blue, Q, I, 7 Diad Blue (acidic dye above 22°C), 0, Engineering, Basic Proof ＼ 0, X,
Basic Blue 9, C8 Engineering, Basic Blue 19 (
basic dye), 0. Modern Plue 48 (mordant/acidic mordant dye), 0. Engineering, Disperse Blue 1. c.
, Work, Disperse Blue 3, C9 Work, Disperse Blue 5C or higher disperse dye), C1 Work, Solvent Blue 2
, C0, Solvent Blue 11.0, Solvent Blue 12 (the above [1 dye) 72, etc.].

A low melting point substance such as paraffin wax or water glass may be added to the colorant solution or dispersion in order to prevent release of the internal eyelids or to provide some binding force to the image receptor. The content of the coloring agent in the colored sub-solution or fractional solution is 0.005~
10 weights - preferably 0.01 to 5 weight arcs.

In addition, the first wall membrane (inner wall layer) f: The film-forming polymer substances that constitute the above-mentioned 7-rabbit 7-gum, gelatin shell, collagen, casein, fibrinogen, hemoglobin, stream amino acids, agar, alginic acid soda,
carrageenan, hunnyarulose, nylin, tet chopsticks,
Polyurethane, polycarbonate), formalin naphthalene sulfonic acid condensate, 7R resin-full beef resin, silicone 1J corn resin, maleic anhydride meats polymer (ethylene, vinyl methyl ether) IA'), acrylic acid,
Examples include methacrylic acid-based copolymers, polyvinyl chloride, polyvinylidene chloride, polyethylene, polystyrene, polyvinyl 7-heptadal, 7-acrylic 7-mide-1 polyvinylbenzenesulfonic acid, polyvinyl alcohol, and synthetic rubber. .

Furthermore, the second wall film (outer wall film) f: constituent synthetic resins include carbonate, polyester, polyamide,
Polyether, polyolefin, polystyrene, styrene-acrylage copolymer, styrene-methacrylate copolymer 1 Styrene-ethylenically unsaturated olefin copolymer, styrene-vinyl ester copolymer, styrene-vinyl ether copolymer, styrene- acryloni)
Lyle copolymer, styrene-meta-7cryloni-F Lyle copolymer, styrene-7cryl-7mide copolymer, styrene-α
- Methylene fatty acid monocarboxylic acid ester copolymer, styrene-vinylidene halide copolymer, polyvinyl acetate, copolymers of two or more of these, or mixtures of these polymers, etc. [Examples include: Used in the form of an aqueous dispersion 〇The magnetic substances mixed into this synthetic resin include metals such as cobal F1 iron and nickel, aluminum cobalt, copper, iron, lead, magnesium, nickel, M, Ml, gold, silver, 7inches, beryllium, bis! s, cadmium, calcium, manganese, selenium,
'Alloys or mixtures of metals such as titanium, tungsten, vanadium and zirconium, fluonium oxide,
Metal compounds including metal oxides such as iron oxide, copper oxide, nickel oxide, zinc oxide, zirconium oxide, titanium oxide and magnesium oxide, refractory nitrides such as chromium nitride, expanded tungsten carbide and silica carbide. Examples include hard carbides, ferromagnetic ferrites, and mixtures thereof.

Further, it is preferable to use a colored magnetic material as the magnetic material in order to improve the sharpness of the color.

Suitable colored magnetic materials for use in colored developers include iron oxide (Pegala) and N for mazenp.
1 surface coated with oxidized steel, 1 surface coated with cadmium red adsorbed on N1, 1 cyanide coated with cobalt and its compounds, yellow coated with iron oxide, and N1 coated with cadmium yellow. In both cases, fine particles are generated using a precipitation method to produce a glossy surface.
After crushing, chemical surface treatment is applied.

The content of the magnetic material is suitably within a range of 70 to 70% by weight with respect to the amount of developer gold, preferably 50 to 70% by weight≦.

Next, the latter powder developer will be described.

A powder developer is one in which a transparent resin contains a colorant and a fraction of a magnetic substance or a colored magnetic substance.

As the magnetic substance contained in the developer, one that effectively selectively reflects the color of the colored developer when the developer is stacked is used, and as the resin of the developer, the color of the magnetic substance [redemption enhancement] is used. A material with a striking color or a mixture of such dyed or colored materials was used to enable direct overlapping.

The magnetic material preferably has a particle size of 0.5 to 10μ, a smooth linear or spherical surface, and a glossy surface. Such particles can be prepared by placing a colorless or colored magnetic material in a colored transparent resin or a transparent resin mixed with dyes or pigments, or by coating the surface of the magnetic material with a transparent or semi-transparent coloring agent and placing it in a colorless transparent resin or a colored magnetic material. If this is insufficient, it can be made by placing it in a colored transparent resin or a transparent resin mixed with dyes or pigments. When used as a developer for overlaying, the ratio of the magnetic material to the resin is suitably 1 to 50 in volume specific pressure to the magnetic material IK, and the particle diameter of the developer is 5 to 20 .mu.m.

The magnetic material and coloring agent used in the above developer are the same as those in the microcapsule developer, and the colored magnetic material is also the same.

Examples of resins used include phenol, polyester, styrene, fluorine)-17 resin, and polyethylene.

In addition, when a two-component developer is used, one developer does not necessarily contain a magnetic material or a colored magnetic material.

It is brown and white. The copying process of the present invention is performed as follows.

There are two known methods for forming electrostatic latent images.
One method is to mutually change the spectral sensitivity characteristics of a conductive substrate and a conductive substrate.
After performing primary charging to a predetermined polarity on a photoreceptor made of two photoconductive layers laminated with a concentration of 1%, secondary charging is applied to the photoreceptor with the opposite polarity to each photoconductive layer on the photoreceptor. Layer K, electricity 2
The superimposed layers are formed so that their bipolar moments are opposite to each other, and then the original is irradiated with light to reduce the photoreceptor surface potential to approximately 0 at a portion corresponding to the background of the original, and to correspond to each color image gIK. There is a method in which an electrostatic latent image portion is formed by a photoreceptor surface potential distribution having opposite polarities.

Another method is to use a recording electrode on the photoreceptor and form an electrostatic latent image using positive and negative placement signals.

The electrostatic latent image created by one of the methods described above is developed with a composite developer, and after being corona-charged with a corona charger to align it to one polarity, it is transferred to recording paper and fixed. let The photoreceptor is cleaned by a cleaning device, and the remaining electrostatic latent image is removed by a charge-eliminating corona charge IEa, and the photoreceptor is used repeatedly.

The present invention will be explained below using Examples.

<Example 1> A positively charged black developer was mixed, heated, fermented and cooled, then crushed and classified to have an average particle size of 15 μm, and 0.2 tsp of silica was added as a KR mobilization agent. I used something similar.

A negatively charged red developer was classified to have an average particle size of 15 μm, and 0.2 μm of silica was added thereto as a stiffening agent.

These developers were mixed in equal proportions and developed in a developing device shown in FIG. 114. It is desirable that the mixing ratio be close to equivalence, and even if it is large, it is especially desirable that the deviation does not exceed 2:8.

Figure 4 is a schematic configuration diagram showing an embodiment of the present invention,
4 is a recording electrode, and the recording signal 5 of e and e causes the photoconductor! ), an electrostatic latent image 3 is created. 2 is a developing device for developing the electrostatic latent image 3; 6 is a corona charger for aligning the charge polarity of the developer; 7 is a recording paper made of plain paper; 8 is the recording paper; For transcription; Rona load IE device,
9 is a fixed/worn heater, 10 is an i$ cleaning fur brush,
Reference numeral 11 is a 010 charger for static elimination.

In the experiment, a polyethylene tele-7 (PET) film with a thickness of δμ and aluminum vapor-deposited on the back was used as the dielectric film.
The electrostatic latent images 4 at 400 V and -400 V were developed with a developing machine 5 using a black 5Am agent.

A sleeve 2-d that rotates as a magnetic brush developer or a supply roller, a fixed magnet 2-e inside the sleeve 2-d, a sleeve 2-f that rotates as a fourth roller, and an electrostatic latent image 3 inside the sleeve 2-d facing each other. It is composed of a fixed magnet 2-1, and conveys the developer for development.

During development, the gap between the photoconductor and the sleeve 2-f is maintained at 0.3 mK, and in this state KO, 2soglF) the developer layer is fed into the developing roller ~ α, 500H! AC and -500v
This was done by applying a DC voltage of . When this alternating current was not applied, red developer was seen mixed in the image area, and the sharpness of the image was also low.

Next, each developer is charged with a corona charger 6 and e
After that, the image was transferred onto a recording paper 7 using a transfer corona charger 8, and was heated and fixed using a fixing heater 9, thereby recording.

Further, static electricity was removed by setting the static electricity removal corona charge IE device 11 to zero potential and applying alternating current (IQ) current.

When developing only ■ with black developer, the voltage applied in the above process should be from -500v to +500vK! This was done by repeating.

As explained above, in this embodiment, positive and negative electrostatic latent images are created on the surface of a photoreceptor, and an alternating electric field is used with a double-layered developer depending on the polarity of the 3#! developer under a magnetic field. Develop it,
Align the polarity of the developer to one polarity by corona charging,
It was transferred to recording paper and fixed.

Therefore, high-quality recording on plain paper (two colors) can be performed at high speed.

Further, when adhesive transfer is used as the transfer means, the corona charger 6.8 becomes unnecessary.

<Embodiment 2> In the present invention, electrostatic latent images with different polarities can be developed sequentially, but they can also be developed simultaneously. Here, we will discuss an example of developing a bipolar electrostatic latent image created by electrophotography.

[Figure 5 is a schematic diagram showing the configuration of an embodiment of this generator. 1
3 is an optical system combining red light 13-8 and corona charge @ 13-b, 15 is a cop charge S% 14 is an exposure system, and these form an electrostatic latent image 3 on the photoreceptor 1. . i
is a developing device for developing the electrostatic latent image 3; 6 is a corona charger for aligning the charge polarity of the developer; 7 is a record @IIi made of plain paper; 8 is for transferring onto the recording paper 7. 9 is a heater for fixing, 10 is a tour brush for cleaning, and 11 is an optical system combining a corona charger 11-b for static elimination and a white light 11-b.

The electrostatic latent image was formed as follows.

An aluminum plate is used as a conductive base, and the KM degree is 99.
99-90% selenium was deposited to a thickness of 12 μm. On this selenium layer, polyvinylcarbazole-trinitrofluorenone was coated to a thickness of 18 μm. Polyvinyl carbazole and trinitrofluorenone i; f) The mixing ratio is 0.1 mole of trinitrofluorenone per mono ff - unit of polyvinyl carbazole.Selenium layer, polyvinyl carbazole-trinitrofluorenone layer (OP below)
(abbreviated as C layer) are both polar chargeable, and OF2
The layer is translucent.

This photoreceptor 1 & 13-+a, Toshiba red filter-
While uniformly exposing with red light obtained by VR64K,
6. OKVノ=y o +load 11i13- b K
J: Re+700V.

K primary charging, then charging to -400V with a -5.2KV corona charger in the dark ◎Next, exposure system 1
When exposure was carried out using a light image of a document having red iii* and black image lines on a white background according to 4, the photoreceptor surface potential at the part corresponding to the white background of the document was -30V, and the red image side A.
The electrostatic latent image portion corresponding to color tiii is +
An electrostatic latent image was formed with a photoreceptor surface potential distribution of 300 V and -400 V.

This was developed using the composite developer used in Example 1 in a magnetic brush developer 2. The magnetic brush developing device 2 includes a sleeve 2-d that rotates as a supply roller and a magnet 2 fixed inside the sleeve 2-d.
-e, two sleeves 2-f rotating as the current four-ra
It is comprised of a fixed magnet 2-g which faces an electrostatic latent image 3 inside thereof, and conveys the developer for development. For development, the photoconductor L and sleeve 5-111ff are held at 0.3 mK and a developer layer of 3IAK O, 4ym is fed into the photoreceptor.
This was carried out by applying a 0.4 KV 1500 Hz alternating current and a ±soo v direct current voltage to each developing roller. When this alternating current was not applied, a mixture of black developer and red developer was observed, and the sharpness of the image was also low. Next, each developer is corona charged with gS
6 to align the polarity with e, and then transferred to a recording paper 7 with a transfer corona charge lI8, and was heated and fixed by a fixing heater 9 to perform recording. Further, static elimination was performed by setting the static elimination corona charge l9111' to zero potential and applying an alternating current corona and white light.

As explained above, in Example 2, positive and negative electrostatic latent images are created on the surface of the photoreceptor under a magnetic bias that prevents fogging, and an alternating electric field is applied to improve image quality with a composite developer depending on the polarity of the developer. The polarity of the developer was adjusted to one polarity by corona charging, and the developer was transferred and fixed onto recording paper. Therefore, there is an advantage that high-quality two-color recording can be performed on plain paper at high speed.

Also, when adhesive transfer is used as the transfer means.

The corona chargers 6 to 8 become unnecessary.

[Brief explanation of the drawing]

FIG. 1 is a graph showing the relationship between the potential of an electrostatic latent image and the amount of developer, FIGS. 2 and 3 are schematic diagrams of the developing device of the present invention, and FIGS. FIG. 2 is a schematic configuration diagram for detailed explanation. '' is a photoreceptor, 2 is a developing device, 3 is an electrostatic temperature compensator, 4 is a recording electrode, 5 is a recording signal, 6 is a corona charger, 7 is a recording paper, 8 is a corona charger for transfer, 9 is for fixing 10 is a fur brush for cleaning, 11 is a corona charger J2 for static elimination, is an AC power source, and 13 is an optical system. Agent Yoshimi Kuwabara 1. Album 2 Figure 220 4. 4. Amendment to figure procedure 1 'Do I'l's clothes Koro Showa 56; Relationship with old/lf I'1 which is a supplementary market Patent applicant I1 Location Higashi 5; Shichito Shinjuku-ku Nishishin 11 I l i'
lI'26 No. 2 Name (+271 Konishi 6") J:
Nobuhiko Kawamoto, Representative Director of the Company Limited Supplement III Act, Vol. Column 7, "Explanation" Contents of the amendment (1) Correction of the drawings As shown in the attached sheet (2) In the specification, the words "electrostatic tank g14" on the 19th line of the first page of the amendment have been replaced with "electrostatic thermal compensation 3"
” and corrected. The third line on the same page, which says ``Genjoki 5,'' has been corrected to ``Genuine #I 2.'' On page 25, line 19, the text ``black genrenji'' has been corrected to ``red genrinji.'' wE page 28, line 3, it says, ``With a charger,'' ``Charger 15.
So,” he corrected.

Claims (1)

[Claims] (1) Colored particles charged to one polarity are selectively extracted from colored particles having different charge polarities, and the extracted colored particles are used to charge electrostatic charges of different polarity on an image support. An electrostatic charge image developing method characterized by developing an electrostatic latent image of one polarity of the latent image. (ri) A method for developing an electrostatic image according to claim 1, characterized in that the colored particles contain a magnetic substance. The method for developing an electrostatic image according to claim 1 or 2.(4) The above-mentioned colored particles are colored in different colors. A method for developing an electrostatic image according to claim 3. (Evening method) Charged image developing method. (6) Claims 1, 2, 3, 4, or 5, characterized in that the development of the colored particles having different charging polarities is performed simultaneously. The developing method according to claim 1. σ) The colored particles having charge polarities different from each other contribute to the development gI! except for the charge polarity. section,
The developing method according to item 2, 3, 4, 5, or 6.